The present invention relates to a semiconductor integrated circuit device and a technology for manufacturing the same and, more particularly, to a technology which is effective if applied to a semiconductor integrated circuit device having an electrically writable/erasable nonvolatile memory. The nonvolatile memory is disclosed on pp. 311 to 314 of IEDM (International Electron Device Meeting), Technical Digest, 1991, for example.
The semiconductor integrated circuit device having the nonvolatile memory of that kind is constructed to have a memory array, in which are arranged in a matrix shape a plurality of nonvolatile memories composed of MISFETs having a first gate insulating film, a floating gate, a second gate insulating film and a control gate, and to have its memory array divided into a plurality of blocks composed of at least one word line to shorten the access time and improve the reliability.
In each of the blocks of the aforementioned memory array, the nonvolatile memory has its source and drain connected with a first data line formed as a buried layer in a semiconductor substrate, for example, and the first data line is connected through a transfer MISFET (i.e., Metal-Insulator-Semiconductor Field Effect Transistor) with a second data line made of a conductive material such as aluminum (Al). And, the selection of each block of the memory array is carried out by turning ON/OFF the transfer MISFET.